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 A057819 a(0)=4, a(1)=9, a(n) = 4a(n-1) - a(n-2). 0
 4, 9, 32, 119, 444, 1657, 6184, 23079, 86132, 321449, 1199664, 4477207, 16709164, 62359449, 232728632, 868555079, 3241491684, 12097411657, 45148154944, 168495208119, 628832677532, 2346835502009, 8758509330504, 32687201820007 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Tanya Khovanova, Recursive Sequences Index entries for linear recurrences with constant coefficients, signature (4,-1). FORMULA G.f.: (4-7x)/(1-4x+x^2). - Philippe Deléham, Nov 16 2008 a(n) = -(1/6)*sqrt(3)*(2-sqrt(3))^n + (1/6)*sqrt(3)*(2+sqrt(3))^n + 2*(2-sqrt(3))^n + 2*(2+sqrt(3))^n, with n >= 0. - Paolo P. Lava, Nov 20 2008 MATHEMATICA Transpose[NestList[{Last[#], 4Last[#]-First[#]}&, {4, 9}, 40]][[1]]  (* Harvey P. Dale, Mar 09 2011 *) CROSSREFS Sequence in context: A149119 A149120 A219151 * A129196 A119574 A006393 Adjacent sequences:  A057816 A057817 A057818 * A057820 A057821 A057822 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Nov 09 2000 STATUS approved

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Last modified October 20 23:28 EDT 2020. Contains 337910 sequences. (Running on oeis4.)